diff --git a/hadoop-common-project/hadoop-common/CHANGES.txt b/hadoop-common-project/hadoop-common/CHANGES.txt
index 8043a28077a..b936e307f76 100644
--- a/hadoop-common-project/hadoop-common/CHANGES.txt
+++ b/hadoop-common-project/hadoop-common/CHANGES.txt
@@ -505,6 +505,9 @@ Release 2.0.3-alpha - Unreleased
     HADOOP-9135. JniBasedUnixGroupsMappingWithFallback should log at debug
     rather than info during fallback. (Colin Patrick McCabe via todd)
 
+    HADOOP-9152. HDFS can report negative DFS Used on clusters with very small
+    amounts of data. (Brock Noland via atm)
+
 Release 2.0.2-alpha - 2012-09-07 
 
   INCOMPATIBLE CHANGES
diff --git a/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/DU.java b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/DU.java
index 2c96b0abaf0..9a9f1e3efc7 100644
--- a/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/DU.java
+++ b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/DU.java
@@ -136,7 +136,7 @@ public long getUsed() throws IOException {
       }
     }
     
-    return used.longValue();
+    return Math.max(used.longValue(), 0L);
   }
 
   /**
diff --git a/hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/fs/TestDU.java b/hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/fs/TestDU.java
index de3d5566eb5..71024acd9e6 100644
--- a/hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/fs/TestDU.java
+++ b/hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/fs/TestDU.java
@@ -103,4 +103,12 @@ public void testDU() throws IOException, InterruptedException {
         duSize >= writtenSize &&
         writtenSize <= (duSize + slack));
   }
+  public void testDUGetUsedWillNotReturnNegative() throws IOException {
+    File file = new File(DU_DIR, "data");
+    assertTrue(file.createNewFile());
+    DU du = new DU(file, 10000);
+    du.decDfsUsed(Long.MAX_VALUE);
+    long duSize = du.getUsed();
+    assertTrue(String.valueOf(duSize), duSize >= 0L);
+  }
 }